So while I go to run a game under Snes9X, then I press my "fn" key followed by "1" to disable sound channel 1, this only brought up the save state menu. Even trying the F1-F4 for the background only toggled the brightness or dashboard for the Mac.

I searched many thing on the internet:

Changing key mapping for snes9x mac

disabling mac function [ or "f" ] keys

I had many results that either brought me to the above, showed me how to change the "keyboard layout" or just how to "Use all F1, F2, ets. keys as standard function keys".

So after many weeks of searching and seeing the same thing, I finally saw what I needed as said to myself "i'm so stupid"

Here is what I was looking for......its a key mapped fn key for Snes9X

So, holding down the "/" key and pressing 1 turned off sound channel number 1!